#all{
    width:980px;
    margin: 0 auto;
}
#body_head{
    width:980px;
    height:100px;
}
#body_body{
    width:980px;
    height:500px;
}
#body_left{
    width: 250px;
    height: 500px;
    float: left;
}
#body_right{
    width:730px;
    height:500px;
    float:left;
}
#foot{
    width:980px;
    height:20px;
}